The present invention relates to tumbling mills, and in particular to tube or ball mills for wet and dry grinding systems and having many fields of application such as ore processing for the mining and metallurgical industry, providing closely graded or uniform particles for flotation processes, coarse sand production for glassworks, rock grinding for lime and cement works, phosphates, apatite, heavy spark, talc, pirophyllite, or the like, coal grinding, gypsum pulverization, cement production, slag and ash grinding, and magnesium oxide grinding.
The present invention relates in particular to that type of tumbling mill which has at least one milling chamber of polygonal cross section provided with rounded corners and defined by a series of rings each of which includes a row of plates circumferentially distributed about the axis of the mill, with the milling action taking place as a result of the falling and rolling movement of the milling bodies.
Mills of the above general type which have an interior hollow space of polygonal cross section, particularly square cross section with rounded corners are already known. With such mills of relatively large diameter there are large dead spaces so that such mills have only a relatively low volumetric efficiency. Moreover, with such conventional mills the bearings for the rotary mill are stressed to an excessively high degree while the number of impacts between the milling bodies and material to be milled is relatively small for each revolution and at the same time the impacts are not uniformly distributed during each revolution.